Anionic polymerization is a well known technique for the polymerization of various monomers, including acrylic-type monomers. Anionic polymerization may be used for making relatively mundane polymers such as molding resins. Anionic polymerization, however, often offers the possibility for excellent control of polymer architecture. Such polymerizations, however, often must be run at very low temperatures, which has limited it commercial application.
The control of polymer architecture allows the preparation of more sophisticated polymers such as block copolymers, which are useful for modifying the surface properties of other polymers. Block polymers, for example, are useful as compatibilizers and as color or pigment dispersants for various inks and coatings.
Anionic polymerization is potentially useful for the control of polymer architecture because, during polymerization under optimal conditions, the growing polymer chain is "living" or, in other words, has a "living end." This means that, under the polymerization conditions, the end of the polymer is a relatively stable group which causes further polymerization. At higher temperatures, however, these living ends have tended to become unstable. Methods for the improvement of anionic polymerization, particularly methods which allow the use of higher temperatures, are, therefore, desired.
General descriptions of anionic polymerization, with respect to methacrylates, can be found in R. A. Haggard, et al., Progress in Organic Coatings, vol. 12, p. 1-26 (1984) and G. D. Andrews, et al., New Monomers and Polymers, p. 357-380 (Plenum Publishing Corp. 1984).
H. Ozaki, et al., Macromolecules, vol. 25, p. 1391-1395 (1992) describe the polymerization of methacrylate esters which contain alkoxysilane groups at -78.degree. C.
D. J. A. Raj, et al., Macromolecules, vol. 25, p. 2774-2776 (1992) and M. T. Reetz, et al., Angew. Chem. Int., Ed. Engl., vol. 27, p. 1373-1374 (1988) describe the anionic polymerization of various methacrylates in the presence of large cations. These polymerizations, however, are not believed to be living and are, therefore, not able, or not expected, to produce useful block copolymers.